A detection system for containers or vehicles loaded with goods is a main detection device needed by the customs.
Nowadays, the commonly used detection device is such an inspection system that a single radiation source is used for radiation imaging. However, an inspection system using one radiation source for radiation imaging can only get simplex and limited information. Moreover, since radiation detection is conducted on the object in only one direction by a single radiation source, the particular shape, size, and density of the detected object cannot be shown stereoscopically, and the types of the detected objects cannot be identified accurately or rapidly. Thus, the inspection system with a single radiation source for radiation imaging has a low ability of recognizing objects, and thus has a poor effect on the security inspection of the containers or vehicles loaded with goods.
An inspection system with two radiation sources for radiation imaging has been known. Generally, the inspection system with two radiation sources for radiation imaging comprises one ray source provided above the object, and the other ray source provided on one side of the object. This structure enables the inspection system to obtain projection information of the object in two directions at the same time, thus making up for the inspection system with a single radiation source for radiation imaging. However, the field angle of the ray source in an overhead lighting system is relatively small, to the disadvantages of spreading out the object in a detector for widely imaging. Moreover, regarding the containers or vehicles loaded with goods, since their sizes are large, the size of the inspection system with two radiation sources for radiation imaging required is also large, such that the inspection system has a very heavy weight and is difficult to move. Therefore, a huge trailer is usually required by the inspection system with this kind of structure to drag dozens of tons of containers or vehicles loaded with goods, to pass through the inspection system, resulting in a complex inspection system with a complicated operation and a high cost.